Like any big infrastructure project, the $783-million price tag for the Capital Regional District’s sewage treatment project, recently rebranded as Seaterra, is a floating target.

The CRD is nonetheless moving forward with this budget number to gauge bids from contractors hoping to build elements of the system. It’s the basis for the one-third funding from each of the provincial and federal governments and from properties to be using the Greater Victoria sewer system.

Seaterra program director Albert Sweetnam told a Black Press editorial board that the real cost is expected to be plus or minus 25 per cent of the budget.

That’s nearly $196 million either way, and previous provincial projects suggest the costs will migrate only one way: upward.

We don’t want to sound like Henny Penny, crying that the sky is falling, but a chunk of that plus-or-minus buffer has already been accounted for. This, a few years before the vast majority of construction on this massive project is scheduled to begin.

The CRD board last week bumped up the treatment project cost by $38 million with its decision to not allow biosolids fertilizer created in the CRD to be used in the CRD. Seaterra said its hand is forced to plan for a resource recovery centre at Hartland Landfill that is required to do a lot more than originally budgeted.

The CRD board’s somewhat baffling decision shows just how easy it is for millions to be tacked on to a project’s budget.

Taxpayers in the core municipalities are on the hook for any cost overruns above $783 million, and senior government contributions don’t include a 25-per-cent buffer.

Some municipal jurisdictions have already begun billing for sewage treatment as a way to spread out the tax burden.

It seems now there’s a good chance that burden may have to be spread out longer than originally expected for a project that is substantially more expensive, while barely out of the gates.